<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>customCoalesce</title>
</head>

<body>
    <div>打开浏览器控制台查看结果</div>
    <script>
        const coalesceFactory =
            valid =>
                (...args) =>
                    args.find(valid);
        const customCoalesce = coalesceFactory(
            v => ![null, undefined, '', NaN].includes(v)
        );
        console.log(customCoalesce(undefined, null, NaN, '', 'Waldo'));
    </script>
</body>

</html>